1. Field of the Invention
The present invention relates in general to shower head constructions and in particular to a new and useful massage shower head comprising a mechanism for producing pulsating water jets by means of a valve rotor which is mounted for free rotation and axial play directly adjacent a nozzle plate having a plurality of jet forming nozzle bores, and which is provided with radial wall elements and with a segmental closing disk, and, at the upstream side of which, water guiding elements are provided which produce a rotary water motion in the space accommodating the rotor.
2. Description of the Prior Art
In a known nozzle head of this kind (German Auslegeschrift No. 1 027 364) which is intended particularly for underwater passage, the segment-shaped closing disks of the valve rotor are disposed closely adjacent the inside surface of the nozzle plate in which the water outlets are provided. In other shower heads of the prior art (German Offenlegunsschrift Nos. 2,329,258 and 2,342,612, and U.S. Pat. Nos. 2,878,006; 3,762,648; and 3,801,019), the valve members of the valve rotors are also designed as flat disks of circular-sector or ring-segment shape which are disposed closely adjacent the inside plane surface of the nozzle plate having paraxial nozzle bores, and provided with substantially radially extending wings or wall elements acting as turbine blades. In all these known valve rotors provided with sectorial or ring-segment disks, regardless of the various, always multiple, inlet channels which are directed against the rotor wings obliquely radially or obliquely axially, considerable bearing friction is produced due to the water pressure acting in axial direction on the closing disks of the valve rotors. While the closing disks having a diagonally symmetrical surface distribution, this friction problem may be solved in a fairly satisfactory manner with corresponding expenses, for example, by providing a low-friction point or pivot support for the valve rotor, with closing disks having a diagonally unsymmetrical surface distribution, such as provided in a design of the prior art (German Offenlengungsschrift No. 2,329,258). For reducing the friction forces which produce a strong braking effect, special sliding disks are needed in addition to combined ball and journal bearings. Irrespective of the additional costs connected thereto, this cannot ensure a rotation of the valve rotor under any circumstances, particularly such as a lower water pressure, because of the large contact area between the inside of the nozzle plate and the closing surface of the closing or slide disk and the adhesion or static friction forces thereby produced. Such disturbances in function may be expected also with another known design (U.S. Pat. No. 3,801,019) where the valve rotor comprises a closing member in the form of a ring segment extending through about 180.degree. and placed directly, without any guidance, in flat contact with the plane inside surface of the nozzle plate.
It is further known to reduce the "sharpness" of the jet pulses by providing a larger distance between the closing disk and the inside surface of the nozzle plate (U.S. Pat. No. 2,878,066, Col. 4). For this purpose, the valve rotor of the prior art is provided with an axially adjustable conical bearing permitting, in addition, the compensation of any wear of the support.